CODEWITHSUNDEEP
javaregex-greedysingle-quotesnegative-lookbehind
sigismund
sigismund

Reputation: 19

A quantifier inside a lookbehind makes it non fixed width

I am trying to write condition in look behind to prevent space removing in quotes and after specific keywords.

For example, I have a string str = "client_id like 'TACIENT 1%' or client_id < 'TACLIENT'" ; Then I use regex: (?i)(?<!(eq|ne|<|>|like))\s(?!(eq|ne|<|>|like)) and output is: client_id like 'TACIENT1%' or client_id < 'TACLIENT'

But should be without space removing inside quotes: client_id like 'TACIENT 1%' or client_id < 'TACLIENT'

So regex to find text in single quotes is: '(?:[^']|\.)'* but when I put this regex in look behind: (?i)(?<!(eq|ne|<|>|like|'(?:[^']|\.)'))\s(?!(eq|ne|<|>|like))* I have an error that: "a quantifier inside a lookbehind makes it non fixed width" . When I put '?' after '*' quantifier it also doesn't helps So is there is any alternative way to handle it?

Upvotes: 1

Views: 1711

Answers (1)

The fourth bird
The fourth bird

Reputation: 163577

Instead of using a lookbehind assertion with a quantifier, you can use a capture group to match from '...' to "get that out of the way" and then use that capture group in the replacement.

The alternative will match a whitespace char with the assertions to the left and the right.

('(?:[^'\\]*(?:\\.[^'\\]*)*)')|(?<!eq|ne|[<>]|like)\s(?!eq|ne|[<>]|like)

Regex demo | Java demo

Upvotes: 0

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